Capillary tube cutting and feeding apparatus

ABSTRACT

A length of capillary tubing is mounted to an apparatus, being carried by a reciprocable carriage and a fixed support serving as a guide. The carriage and support have releasable unilateral respective first and second grab means. The grab means are effective in opposite directions of axial movement of the length of tubing so that movement of the carriage toward the support will hold the length of tubing on the carriage but permit the length to slip past the second grab means, but upon return movement of the carriage the second grab means locks the length in position and the first grab means permits slipping movement of the length of tubing relative to the carriage. In this manner a forward stroke of the carriage will feed a length of tubing past the support and a return, or rearward stroke will return the carriage without concurrent movement of the length of tubing. The length fed, at most equals the length of the forward stroke, but can be varied by suitable means, for example, for the purpose of feeding a small end for trimming. A cutter is driven by and synchronized with return movement of the carriage to score the fed length of tubing. The apparatus includes means supporting a cuvette or carrier into which the tubing end is inserted during the stroke. Means are provided laterally to strain the short free end of the length of tubing beyond the score line to cause the short end to break off, either falling into waste in the case of trim, or being captured in the cuvette in the case of a regular measured length. Means are provided to control the length fed by the carriage.

United States Patent Gilford et al. 51 June 6, 1972 [54] CAPILLARY TUBECUTTING AND Primary Examiner-Frank T. Yost FEEDING APPARATUSAttorney-Silverman & Cass [72] Inventors: Saul R. Gilford; Ignacio P.Echeagaray, 57 ABSTRACT both of Oberlin, Ohio A length of capillarytubing is mounted to an apparatus, being Assigneei Gino"! InstrumentLaboratories, 's carried by a reciprocable carriage and a fixed supportserving Oberlin, Ohio as a guide. The carriage and support havereleasable unilateral [22] Filed: Aug. 18, 1969 respective first andsecond grab means The grab means are effective in opposite directions ofaxial movement of the [21 Appl. No.: 850,884 length of tubing so thatmovement of the carriage toward the support will hold the length oftubing on the carriage but permit the length to slip past the secondgrab means, but upon [52] US. Cl ..225/96.5, 83/231, 83/277 returnmovement of the Carriage the Second grab means locks [51] Int. Cl. thelength in position and the first g means permits pp g [58] Field Searchmovement of the length of tubing relative to the carriage. In 83/411;225/965 98 this manner a forward stroke of the carriage will feed alength of tubing past the support and a return, or rearward stroke will[56] References Cited return the carriage without concurrent movement ofthe len th of tubin The len th fed, at most equals the length of UNITEDSTATES PATENTS the forward str oke, but c an be varied by suitablemeans, for 1,177,293 3/1916 Anderson 83/277 X example, for the purposeof feeding a small end for trimming. 7 23 1924 Overton 33 277 x A cutteris driven by and synchronized with return movement 1,650,556 11/1927 vv83/231 X of the carriage to score the fed length of tubing. Theapparatus 1,968,479 7/1934 Dickerman H 83/277 X includes meanssupporting a cuvette or carrier into which the 2,686,246 8/1954 Souter u83/277 X tubing end is inserted during the stroke. Means are provided2,871,622 2/1959 Smger et al 225/96 5 laterally to strain the short freeend of the length of tubing 3 512 438 5/1970 Burdge u 83/277 X beyondthe score line to cause the short end to break off, either falling intowaste in the case of trim, or being captured FOREIGN PATENTS ORAPPLICATIONS in the cuvette in the case ofa regular measured length.Means are provided to control the length fed by the carriage. 104,8053/1917 Great Britain ..225/96.5

7 Claims, 2 Drawing Figures CROSS-REFERENCE TO RELATED APPLICATIONS Theonly purpose in referring to other applications herein is to assist inappreciating the nature of the invention and its purposes. None of theseapplications discloses any form of capillary tubing cutting or feedingmechanism, and none is needed to provide any portion of the disclosureof this application.

The applicant herein is the applicant of application Ser. No. 472,294filed July 15, 1965, now US. Pat. No. 3,475,l27, entitled FLUID SAMPLEMEASURING AND DILUTING METHOD AND APPARATUS which discloses and claimsthe basic concept of using accurately cut lengths of capillary tubingfor the measurement of liquids. The apparatus comprises capillary tubingof accurate bores which are filled with sample liquids, such as forexample, blood. Accurately measured lengths of the tubing thus representaccurate volumes of fluid. One such length is placed in a cuvette orcarrier, diluted with a known volume of reagent, and used in makingtests upon the dilution.

The lengths of capillary tubing are filled in any one of severalmethods. Normal filling by capillary action can be achieved, but is notpreferred. Other methods employ vacuum for this purpose. The methods andapparatus are disclosed in applications owned by the assignee of thisapplication, as follows:

Ser. No. 781,386 filed Dec. 5, 1968 and Ser. No. 830,185 filed May 15,1969.

BACKGROUND OF THE INVENTION The field of the invention is micro-samplingthrough the use of capillary tubing. A relatively long length of tubingis filled with a quantity of fluid, and it is desired to cut the lengthaccurately into shorter lengths so that tests may be performed with thevolumes of fluid entrained. The problems which are involved areprimarily the difficulty in handling lengths of frangible tubing withoutloss of the entrained fluid and without breaking the same, in additionto achieving accuracy in the cut lengths. Contamination is also adifficulty which must be overcome. The invention herein achieves theends sought with simplicity, effectiveness and economy.

SUMMARY OF THE INVENTION The lengths of capillary tubing are insertedone at a time into a machine which in effect divides them into shorterlengths. The machine has a reciprocable carriage that contains aunilateral grab device which opposes movement of the length of tubing inone direction but permits such movement in the other direction. Thecarriage slides on a support and its stroke is adjusted by a suitablestop member. The support also carries another grab device which is alsounilateral in function, but effective in the opposite direction. Thelength of tubing is engaged into the second grab device, a control andrelease device for the operation of the grab means being provided toenable this. Once the two grab devices have engaged the length oftubing, each movement of the carriage will feed a short length of tubingpast the second grab device. At this point there is a platform uponwhich a carrier or cuvette is placed so that as the length is fed pastthe second grab device it is piloted into the cuvette. Spring meansreturns the carriage and unidirection driving means, such as a clutchdevice driven by the carriage movement swings a cutter across the lengthof tubing just before it enters the cuvette. The tubing is now scored sothat placing a lateral strain on the free end will break it off,whereupon it will be engaged in the cuvette. The strain may be appliedby the simple expedient of tilting the cuvette or using a bending yoke.The carriage may operate the bending yoke at the end of its returnstroke. A short length of tubing may be trimmed initially by feedingonly such short length past the second grab means, scoring it andbreaking the trim end off to permit its discard to waste. Short feed maybe accomplished by grab means control and/or using different carriagestroke stop means.

BRIEF DESCRIPTION OF THE DRAMNG FIG. 1 is a highly diagrammatic view ofapparatus constructed in accordance with the invention.

FIG. 2 is a more detailed fragmentary view, albeit diagrammaticillustrating the details of the grab means.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention herein isillustrated in highly diagrammatic form because it is capable of takinga wide range of mechanical form with great variation in mechanicaldetails.

In FIG. 1 the reference character 10 is used to designate the apparatusgenerally. There is a support structure 12 upon which a carriage 14 isadapted to slide. The carriage 14 is biased to move upward by means ofthe spring 16 which is carried on the bracket 18 that also supports anadjustable stop screw 20 by means of which the upward movement of thecarriage is limited. The carriage has a handle 22 which enables thecarriage manually to be pushed downward as viewed in the illustrationagainst the force of the spring 16. When released, the carriage 14 willmove upward. Lever movement may also drive the carriage and operateother parts of the device.

The carriage 14 has a tubing guide 24 mounted thereon so that a longlength of capillary tubing such as shown at 26 may be piloted and fedinto the apparatus 10. The apparatus may be arranged so that the lengthof capillary tubing will be disposed in a horizontal plane instead ofvertical as shown. Accordingly, reference to directions up and down"should be considered only relative, and illustrative of the apparatus.The tubing length 26 is engaged by the upper unilateral grab mechanismshown as a simple block 28 in FIG. 1, but more detailed in FIG. 2. Thegrab mechanism 28 holds the tubing 26 against relative movement when thecarriage is moved downwardly, but will permit the tubing length to sliprelative to the carriage when the carriage 14 is moved upwardly.Accordingly, the block 28 is marked GRAB DOWN."

The bottom stroke of the carriage 14 is limited by the stop member 30mounted on the support. The lower end of the length 26 is engaged intothe lower unilateral grab mechanism represented by the block 32. Thisgrab mechanism is fixed to the support 12 and as shown is marked GRABUP. The mechanism 32 may be identical in construction with the mechanism28 but since it is mounted on a fixed support, its effective operationis in the opposite sense. When the length of tubing 26 moves downwardly,the grab mechanism 32 releases the same and permits such movement, butwhen the tubing length is pulled upwardly, the mechanism seizes the sameand prevents such upward movement. It will be seen that this action isopposite to that of the upper grab mechanism 28. Thus, the operator canstroke the handle 22 and, assuming that the carriage 14 is pushed allthe way to its lower stop member 30, each downward stroke will feed alength of tubing of a dimension equal to the stroke of the carriage pastthe lower grab mechanism 32. Releasing the carriage will cause thespring 16 to pull it upward to its stop member 20 and during thismovement, the length of tubing 26 will be stationary relative to thesupport 12.

An intermediate stop member 33 may be interposed in the path of thecarriage 14 as indicated by the broken line position of said stopmember, to limit the stroke of the carriage 14 for certain purposes.Thus, when first a length of tubing 26 is disposed in the apparatus, itis desirable to cut off a short section of the end to establish areference end for subsequent full stroke cut lengths. Additionally theopen end of the length 26 as it comes from the filling apparatus (notshown) may have become contaminated or dried and it is best to cut itoff. Since the grab mechanism 32 prevents upward movement of the length26, once the length 26 has advanced to said grab mechanism and beensevered, that point is the reference end of the remainder of the length.The trim end is discarded to waste.

Instead of an intermediate stop member 33, independent control of thegrab mechanisms may be used to permit advance of only a short trim endfor the initial movement of the carriage, as will be described.

A cutter wheel 34 mounted on a swinging arm 36 is arranged to moveacross the length of tubing protruding from the bottom of the lower grabmechanism 32. This arm 36 is driven by a suitable linkage 38 through acutter control 40 that is in turn driven by the upper movement of thecarriage 14 through a linkage 42. In one practical device, the cuttercontrol 40 included a one-way clutch mechanism that was quiescent orcocked when the carriage was moving downwardly, but was operative whenthe carriage 14 was moving upwardly after the length 26 had stopped. Theaddition of a rotary rachet mechanism enabled the arm 36 to be swung inone pass for each cycle of back and forth movement of the carriage, andthen to swing in a reverse pass for the next cycle. Many other cutterdrive mechanisms will suggest themselves to those skilled in this art.

A refinement comprised a ratchet mechanism 44 which gave the cutterwheel a slight rotary movement for each pass to present a new surface tothe length of tubing. A suitably designed wheel will rotate slightlywith each pass and not require the ratchet.

A platform 46 is secured to the support 12 and a cuvette or othercarrier 48 of a type which is to receive the broken off length ofcapillary tubing is mounted to the platform to receive the length asbroken off. To break the length off after it has been separated from thebody of the tubing 26 by a score line, one need only laterally strainthe lower end of the tubing, that is-the portion which is protrudinginto the carrier or cu vette 48. This can be done manually, by holdingthe cuvette 48 and tipping itor can be done by an arm or yoke 50 mountedon the platform 46. Many other ways of breaking off the bot tom end maybe used.

After the cuvette 48 has the broken short length in it, it is removedfor further processing and replaced by another cuvette.

In FIG. 2 diagrammatic details of grab mechanisms are shown. As for theupper grab mechanism 28, there is a friction arm 50 which is biased torotate counter-clockwise about the pivot 52 by the spring 54 so thatwhen the length of tubing 26 is in place, the friction surface 56 willengage the side of the length of tubing, clamping the same to theback-up member 58. The slightest upward movement of the length of tubing26 relative to the carriage 14 more tightly wedges the friction arm 50against the back-up member 58, and so the downward movement of thecarriage carries the length of tubing downward also. if there is anyresistance to upward movement of the length 26, as for example whencarriage 14 moves upward and the lower end of the length 26 is heldagainst movement, there is a simple slippage of the carriage relative tothe length 26 because arm 50 tends to rotate clockwise against spring54, releasing length 26.

The lower grab mechanism 32 is constructed in the same way, but has areverse function. There is a friction arm 60 pivoted at 62 and biased tomove in a counter-clockwise direction by the spring 64 bringing thefriction surface 66 into engagement with the tubing and clamping itagainst the backup member 68. Any upward sliding movement of the lengthof tubing 26 more tightly wedges the friction arm 60 against the back-upmember 68 with the length of tubing between. Downward sliding movementof the length of tubing 26 will engage the friction surface 66 and tendto move the arm 60 clockwise against the spring 64, this movementseparating the arm 60 from the back-up member 68. This frees theengagement and the length of tubing 26 readily slides downwardly pastthe grab mechanism 32.

Reviewing again the operation of the apparatus, the carriage 14 is moveddownwardly, the length 26 is grabbed by the mechanism 28 and slips pastthe mechanism 32. When the downward stroke is completed, the carriage 14is pulled upward by the spring 16. The length of tubing 26 is grabbed bythe lower mechanism 32 and held tightly so that it cannot move relativeto the support 12. The carriage moves upward and the mechanism 28 freelypermits passage of the tubing 26 past itself.

A grab control 70 is provided to release the grab mechanism when it isdesired to insert a length of tubing or remove the same and can be usedfor controlling the fed length of tubing. For example, in FIG. 2 theextensions 72 and 74 may be individually moved or moved together torotate the respective arms against their springs to open what might betermed the throats" of the grab mechanisms.

Consider for example an initial condition when the apparatus 10 is to beput into use. By manual or other command or manipulation, the grabcontrol 70 is caused to move the arms 76 and 78 together to the right asviewed in FIG, 1, this action causing the extensions 72 and 74 of theyoke 75 to rotate both of the friction arms 50 and 60 clockwise, openingthe throats and providing a clear space into which a length of capillarytubing 26 may be placed or deposited. Once this has been done, the arms76 and 78 can be moved to the left to cause the length of tubing to begripped for movement axially, that is, lengthwise of the tubing.

As previously mentioned, instead of limiting the stroke of the carriage14 for the purpose of trimming the end of a newly installed length oftubing 26, the grab mechanisms 28 and 32 may accomplish the samefunction. Thus, a lever 80 in the path of the carriage, or evenconnected to the handle 22 could initiate the function of trimming. Forexample, in FIG. 1, the handle 22 may have a lost motion connection withthe carriage 14 at 82 so that the first downward movement engages thelever 80 before the carriage 14 starts to move, and operates the trimcontrol mechanism 84. This mechanism may be any suitable mechanical orelectrical device coupled through a connection 86 with the grab control70. The two alternate locations of this trim control are shown in therespective views.

The operation of the trim control 84 would be to push the arm 76 to theright without pushing the arm 78 so that for a predetermined length ofthe stroke of the carriage 14 downward the grab mechanism 28 is notholding the length of tubing 26, but on the contrary permits it to slippast the throat. At the bottom of the stroke, the arm 76 returns to thenormal position, the lever 50 moves tightly against the tube length andthe friction surface 56 locks the length'in place, Thereafter for theremainder of the stroke of the carriage, the length is fed past the grabmechanism 32. Prior to this time, for the first part of the stroke, thelength did not move at all.

The advantage of this type of trim mechanism over that using a stopmember such as 33 is that the total mechanical stroke of the carriage 14can be the same when trimming or cutting, so that movement of thecarriage may be used to perform other mechanical functions.

The trimming function is performed only once for each length of tubing,such that after one operation the trim control 84 is disabled for theremaining cuts taken of the length 26. The grab control 70 may bemanually operated for these various functions by suitable means, to movethe arms 76 and 78. It will be appreciated that the arms 76 and 78should be moved to the left together after the long dimension of thelength 26 is too short to enable the grab mechanisms 28 and 32cooperatively to function, at which time the remanent section is removedfrom or dropped out of the apparatus 10 to make way for a new length.

The stroke of the carriage and the length of trim may be readilyadjusted by choice of suitable mechanisms.

It will be appreciated that the lengths of tubing 26 contain samplefluids, each length being preferably provided with a sealed end so thatthe fluids are retained during the operation of the apparatus 10. Asstated, the disposition of the length during cutting need not bevertical.

What it is desired to secure by Letters Patent of the United States is:

We claim:

1. A feeding and cutting apparatus for capillary tubing, comprising:

A. a support structure having a carriage reciprocable thereon betweentwo positions defining a stroke of predetermined length,

B. means for moving the carriage from its first position toward itssecond position when desired and return means for returning the carriageto the said first position,

C. means on the carriage for laterally confining a length of capillarytubing having an axial dimension several times the extent of the saidstroke, but permitting lengthwise movement of the length of capillarytubing,

D. first unilateral grab means on said carriage adapted to have thelength of capillary tubing engaged thereby and preventing movement ofthe said length of capillary tubing relative to the carriage in adirection which would tend to move the length of tubing toward saidfirst position but permitting movement of the length of tubing relativeto the carriage in a direction which would tend to move the length oftubing toward the second position,

E. second unilateral grab means connected to said support structure andaligned with and adapted to have the length of capillary tubing engagedthereby but acting upon said length with permitting and preventingfunctions opposite those of said first grab mechanism,

whereby each movement of the carriage from its first position toward itssecond position will feed a portion of the length of capillary tubingpast the second grab means, the axial dimension of said portion at mostbeing equal to the extent of said last-mentioned movement,

F. means for cutting said length to define said portion and enable saidportion to be broken from said length,

G. means for controlling the first unilateral grab means,

l-l. means for controlling the second unilateral grab means,

and

K. means for controlling the trimming of the end of a length of tubing,

L. wherein the cutting means comprise a scoring wheel connected with anddriven by the movement of the carriage.

2. The apparatus as claimed in claim 1 in which the connection betweensaid scoring wheel and carriage is inoperative when said carriage ismoving from its first position toward its second position, but isoperative only when the carriage is returning to its first position,whereby the cutting operation will be performed only when the length oftubing is not moving.

3. The apparatus as claimed in claim 1 in which means are provided torotate the scoring wheel with movement of the carriage to present adifferent cutting edge for each such movement.

4. A feeding and cutting apparatus for capillary tubing, comprising:

A. a support structure having a carriage reciprocable thereon betweentwo positions defining a stroke of predetermined length,

B. means for moving the carriage from its first position toward itssecond position when desired and return means for returning the carriageto the said first position,

C. means on the carriage for laterally confining a length of capillarytubing having an axial dimension several times the extent of the saidstroke, but permitting lengthwise movement of the length of capillarytubing,

D. first unilateral grab means on said carriage adapted to have thelength of capillary tubing engaged thereby and preventing movement ofthe said length of capillary tubing relative to the carriage in adirection which would tend to move the length of tubing toward saidfirst position but permitting movement of the length of tubing relativeto the carriage in a direction which would tend to move the length oftubing toward the second position,

E. second unilateral grab means connected to said support structure andaligned with and adapted to have the length of capillary tubing engagedthereby but acting upon said length with permitting and preventingfunctions opposite those of said first grab mechanism,

whereby each movement of the carriage from its first position toward itssecond position will feed a portion of the length of capillary tubingpast the second grab means, the axial dimension of said portion at mostbeing equal to the extent of said last-mentioned movement,

F. means for cutting said length to define said portion and enable saidportion to be broken from said length,

G. means for controlling the first unilateral grab means,

H. means for controlling the second unilateral grab means,

and

K. means for controlling the trimming of the end of a length of tubing,

L. wherein the carriage movement is vertical, with the first positionbeing higher than said second position, in which the support structureincludes means for mounting a euvette in position to receive the lengthas it is being fed past the second grab means, whereby when broken fromsaid length, said portion will fall by gravity into said cuvette, and

M. including means for applying lateral strain to the said portion.

5. A feeding and cutting apparatus for capillary tubing,

comprising:

A. a support structure having a carriage reciprocable thereon betweentwo positions defining a stroke of predetermined length,

B. means for moving the carriage from its first position toward itssecond position when desired and return means for returning the carriageto the said first position,

C. means on the carriage for laterally confining a length of capillarytubing having an axial dimension several times the extent of the saidstroke, but permitting lengthwise movement of the length of capillarytubing,

D. first unilateral grab means on said carriage adapted to have thelength of capillary tubing engaged thereby and preventing movement ofthe said length of capillary tubing relative to the carriage in adirection which would tend to move the length of tubing toward saidfirst position but permitting movement of the length of tubing relativeto the carriage in a direction which would tend to move the length oftubing toward the second position,

E. second unilateral grab means connected to said support structure andaligned with and adapted to have the length of capillary tubing engagedthereby but acting upon said length with permitting and preventingfunctions opposite those of said first grab mechanism,

whereby each movement of the carriage from its first position toward itssecond position will feed a portion of the length of capillary tubingpast the second grab means, the axial dimension of said portion at mostbeing equal to the extent of said last-mentioned movement,

F. means for cutting said length to define said portion and enable saidportion to be broken from said length,

G. means for controlling the first unilateral grab means,

H. means for controlling the second unilateral grab means,

and

K. means for controlling the trimming of the end of a length of tubing,

L. means to vary the axial dimension of the said portion,

M. wherein said last means include stop means to provide an intermediateposition between said first and second positions.

6. A feeding and cutting apparatus for capillary tubing comprising:

A. a support structure having a carriage reciprocable thereon betweentwo positions defining a stroke of predetermined length,

B. means for moving the carriage from its first position toward itssecond position when desired and return means for returning the carriageto the said first position,

C. means on the carriage for laterally confining a length of capillarytubing having an axial dimension several times the extent of the saidstroke, but permitting lengthwise movement of the length of capillarytubing,

D. first unilateral grab means on said carriage adapted to have thelength of capillary tubing engaged thereby and preventing movement ofthe said length of capillary tubing relative to the carriage in adirection which would tend to move the length of tubing toward saidfirst position but permitting movement of the length of tubing relativeto the carriage in a direction which would tend to move the length oftubing toward the second position,

E. second unilateral grab means connected to said support structure andaligned with and adapted to have the length of capillary tubing engagedthereby but acting upon said length with permitting and preventingfunctions opposite those of said first grab mechanism,

whereby each movement of the carriage from its first position toward itssecond position will feed a portion of the length of capillary tubingpast the second grab means, the axial dimension of said portion at mostbeing equal to the extent of said last-mentioned movement,

F. means for cutting said length to define said portion and enable saidportion to be broken from said length,

G. means for controlling the first unilateral grab means,

H. means for controlling the second unilateral grab means,

and

K. means for controlling the trimming of the end of a length of tubing,

L. means to vary the axial dimension of the said portion,

M. wherein said last means comprise a grab release mechanism operableupon said first grab means to render same inoperative during a portionof said stroke.

7. A feeding and cutting apparatus for capillary tubing,com-

prising:

A. a support structure having a carriage reciprocable cable thereonbetween two positions defining a stroke of predetermined length,

B. means for moving the carriage from its first position toward itssecond position when desired and return means for returning the carriageto the said first position,

C. means on the carriage for laterally confining a length of capillarytubing having an axial dimension several times the extent of the saidstroke, but permitting lengthwise movement of the length of capillarytubing,

D. first unilateral grab means on said carriage adapted to have thelength of capillary tubing engaged thereby and preventing movement ofthe said length of capillary tubing relative to the carriage in adirection which would tend to move the length of tubing toward saidfirst posi tion but permitting movement of the length of tubing relativeto the carriage in a direction which would tend to move the length oftubing toward the second position,

E. second unilateral grab means connected to said support structure andaligned with and adapted to have the length of capillary tubing engagedthereby but acting upon said length with permitting and preventingfunctions opposite those of said first grab mechanism,

whereby each movement of the carriage from its first position toward itssecond position will feed a portion of the length of capillary tubingpast the second grab means, the axial dimension of said portion at mostbeing equal to the extent of said last-mentioned movement,

F. means for cutting said length to define said portion and enable saidportion to be broken from said length,

G. means for controlling the first unilateral grab means,

H. means for controlling the second unilateral grab means,

K. means for controlling the trimming of the end of a length of tubing,

the first and second unilateral grab means each including L. a frictionarm pivotably mounted on the carriage and comprising a friction surface,

M. a spring for biasing the friction arm to move in a counter-clockwisedirection,

N. a back-up member connected to the carriage,

wherein, when the length of tubing is in place the friction surface willengage the side of the length of tubing and clamp it to the back-upmember,

0. the means for controlling the first and second unilateral grab meanseach including an arm, a yoke linked to the arm and having an extensionpositioned such as to engage the pivotable friction arm, wherein whenthe grab control means is caused to move the arm the extension willrotate the friction arm clockwise against the force of the spring so asto open the clamping of the length of tubing.

1. A feeding and cutting apparatus for capillary tubing, comprising: A.a support structure having a carriage reciprocable thereon between twopositions defining a stroke of predetermined length, B. means for movingthe carriage from its first position toward its second position whendesired and return means for returning the carriage to the said firstposition, C. means on the carriage for laterally confining a length ofcapillary tubing having an axial dimension several times the extent ofthe said stroke, but permitting lengthwise movement of the length ofcapillary tubing, D. first unilateral grab means on said carriageadapted to have the length of capillary tubing engaged thereby andpreventing movement of the said length of capillary tubing relative tothe carriage in a direction which would tend to move the length oftubing toward said first position but permitting movement of the lengthof tubing relative to the carriage in a direction which would tend tomove the length of tubing toward the second position, E. secondunilateral grab means connected to said support structure and alignedwith and adapted to have the length of capillary tubing engaged therebybut acting upon said length with permitting and preventing functionsopposite those of said first grab mechanism, whereby each movement ofthe cArriage from its first position toward its second position willfeed a portion of the length of capillary tubing past the second grabmeans, the axial dimension of said portion at most being equal to theextent of said lastmentioned movement, F. means for cutting said lengthto define said portion and enable said portion to be broken from saidlength, G. means for controlling the first unilateral grab means, H.means for controlling the second unilateral grab means, and K. means forcontrolling the trimming of the end of a length of tubing, L. whereinthe cutting means comprise a scoring wheel connected with and driven bythe movement of the carriage.
 2. The apparatus as claimed in claim 1 inwhich the connection between said scoring wheel and carriage isinoperative when said carriage is moving from its first position towardits second position, but is operative only when the carriage isreturning to its first position, whereby the cutting operation will beperformed only when the length of tubing is not moving.
 3. The apparatusas claimed in claim 1 in which means are provided to rotate the scoringwheel with movement of the carriage to present a different cutting edgefor each such movement.
 4. A feeding and cutting apparatus for capillarytubing, comprising: A. a support structure having a carriagereciprocable thereon between two positions defining a stroke ofpredetermined length, B. means for moving the carriage from its firstposition toward its second position when desired and return means forreturning the carriage to the said first position, C. means on thecarriage for laterally confining a length of capillary tubing having anaxial dimension several times the extent of the said stroke, butpermitting lengthwise movement of the length of capillary tubing, D.first unilateral grab means on said carriage adapted to have the lengthof capillary tubing engaged thereby and preventing movement of the saidlength of capillary tubing relative to the carriage in a direction whichwould tend to move the length of tubing toward said first position butpermitting movement of the length of tubing relative to the carriage ina direction which would tend to move the length of tubing toward thesecond position, E. second unilateral grab means connected to saidsupport structure and aligned with and adapted to have the length ofcapillary tubing engaged thereby but acting upon said length withpermitting and preventing functions opposite those of said first grabmechanism, whereby each movement of the carriage from its first positiontoward its second position will feed a portion of the length ofcapillary tubing past the second grab means, the axial dimension of saidportion at most being equal to the extent of said last-mentionedmovement, F. means for cutting said length to define said portion andenable said portion to be broken from said length, G. means forcontrolling the first unilateral grab means, H. means for controllingthe second unilateral grab means, and K. means for controlling thetrimming of the end of a length of tubing, L. wherein the carriagemovement is vertical, with the first position being higher than saidsecond position, in which the support structure includes means formounting a cuvette in position to receive the length as it is being fedpast the second grab means, whereby when broken from said length, saidportion will fall by gravity into said cuvette, and M. including meansfor applying lateral strain to the said portion.
 5. A feeding andcutting apparatus for capillary tubing, comprising: A. a supportstructure having a carriage reciprocable thereon between two positionsdefining a stroke of predetermined length, B. means for moving thecarriage from its first position toward its second position when desiredand return means for returning the carriage to the said first position,C. meAns on the carriage for laterally confining a length of capillarytubing having an axial dimension several times the extent of the saidstroke, but permitting lengthwise movement of the length of capillarytubing, D. first unilateral grab means on said carriage adapted to havethe length of capillary tubing engaged thereby and preventing movementof the said length of capillary tubing relative to the carriage in adirection which would tend to move the length of tubing toward saidfirst position but permitting movement of the length of tubing relativeto the carriage in a direction which would tend to move the length oftubing toward the second position, E. second unilateral grab meansconnected to said support structure and aligned with and adapted to havethe length of capillary tubing engaged thereby but acting upon saidlength with permitting and preventing functions opposite those of saidfirst grab mechanism, whereby each movement of the carriage from itsfirst position toward its second position will feed a portion of thelength of capillary tubing past the second grab means, the axialdimension of said portion at most being equal to the extent of saidlast-mentioned movement, F. means for cutting said length to define saidportion and enable said portion to be broken from said length, G. meansfor controlling the first unilateral grab means, H. means forcontrolling the second unilateral grab means, and K. means forcontrolling the trimming of the end of a length of tubing, L. means tovary the axial dimension of the said portion, M. wherein said last meansinclude stop means to provide an intermediate position between saidfirst and second positions.
 6. A feeding and cutting apparatus forcapillary tubing comprising: A. a support structure having a carriagereciprocable thereon between two positions defining a stroke ofpredetermined length, B. means for moving the carriage from its firstposition toward its second position when desired and return means forreturning the carriage to the said first position, C. means on thecarriage for laterally confining a length of capillary tubing having anaxial dimension several times the extent of the said stroke, butpermitting lengthwise movement of the length of capillary tubing, D.first unilateral grab means on said carriage adapted to have the lengthof capillary tubing engaged thereby and preventing movement of the saidlength of capillary tubing relative to the carriage in a direction whichwould tend to move the length of tubing toward said first position butpermitting movement of the length of tubing relative to the carriage ina direction which would tend to move the length of tubing toward thesecond position, E. second unilateral grab means connected to saidsupport structure and aligned with and adapted to have the length ofcapillary tubing engaged thereby but acting upon said length withpermitting and preventing functions opposite those of said first grabmechanism, whereby each movement of the carriage from its first positiontoward its second position will feed a portion of the length ofcapillary tubing past the second grab means, the axial dimension of saidportion at most being equal to the extent of said last-mentionedmovement, F. means for cutting said length to define said portion andenable said portion to be broken from said length, G. means forcontrolling the first unilateral grab means, H. means for controllingthe second unilateral grab means, and K. means for controlling thetrimming of the end of a length of tubing, L. means to vary the axialdimension of the said portion, M. wherein said last means comprise agrab release mechanism operable upon said first grab means to rendersame inoperative during a portion of said stroke.
 7. A feeding andcutting apparatus for capillary tubing, comprising: A. a supportstructure having a carriagE reciprocable cable thereon between twopositions defining a stroke of predetermined length, B. means for movingthe carriage from its first position toward its second position whendesired and return means for returning the carriage to the said firstposition, C. means on the carriage for laterally confining a length ofcapillary tubing having an axial dimension several times the extent ofthe said stroke, but permitting lengthwise movement of the length ofcapillary tubing, D. first unilateral grab means on said carriageadapted to have the length of capillary tubing engaged thereby andpreventing movement of the said length of capillary tubing relative tothe carriage in a direction which would tend to move the length oftubing toward said first position but permitting movement of the lengthof tubing relative to the carriage in a direction which would tend tomove the length of tubing toward the second position, E. secondunilateral grab means connected to said support structure and alignedwith and adapted to have the length of capillary tubing engaged therebybut acting upon said length with permitting and preventing functionsopposite those of said first grab mechanism, whereby each movement ofthe carriage from its first position toward its second position willfeed a portion of the length of capillary tubing past the second grabmeans, the axial dimension of said portion at most being equal to theextent of said last-mentioned movement, F. means for cutting said lengthto define said portion and enable said portion to be broken from saidlength, G. means for controlling the first unilateral grab means, H.means for controlling the second unilateral grab means, K. means forcontrolling the trimming of the end of a length of tubing, the first andsecond unilateral grab means each including L. a friction arm pivotablymounted on the carriage and comprising a friction surface, M. a springfor biasing the friction arm to move in a counter-clockwise direction,N. a back-up member connected to the carriage, wherein, when the lengthof tubing is in place the friction surface will engage the side of thelength of tubing and clamp it to the back-up member, O. the means forcontrolling the first and second unilateral grab means each including anarm, a yoke linked to the arm and having an extension positioned such asto engage the pivotable friction arm, wherein when the grab controlmeans is caused to move the arm the extension will rotate the frictionarm clockwise against the force of the spring so as to open the clampingof the length of tubing.